Method of clarifying cane molasses for the growing of yeast



Patented Oct..'16, 1928.

- UNITED STATES,

, 1,687,561 PATENT I OFFICE.

CHARLES HOFFMAN, OF TUCKAHOE, NEW .YORK, AND CHARLES N. FIR-BY AND FRANK MERRILL HILDEBRANDT', OF WARREN, OHIO, ASSIGNORS, BY MESNE ASSIGN- MENTS, TO THE FLEISGHMANN COMPANY, OF NEW YORK, N. Y

METHOD OF CLARIFYIN G GA NE MOLASSES FOR THE GROWING F YEAST.

1T0 Drawing.

This invention relates to the method of clarifying crude cane molasses offlthe kind known commercially as black strap molasses, particularly for the purpose of producing cheaper medium for the production of yeast,

and it has heretofore been proposed to utilize the waste products'of the sugar industry for this purpose, as such products are comparatively cheap and contain the necessary sugar content as well as some of the nitrogen and phosphorus necessary for the requirements of the yeast. It hasbeen found, however, that such products, particularly the cane molasses which is the cheapest and most abundant of the sugar by-products, contain various impurities which are unfavorabletothe growth of yeastand also discolor it and impart to it an unpleasant flavor which makes yeast grown in such mediums unsuitable for use in bread. The elimination of such im= purities is not so important in the production of spirits, as for bakers yeast where the yeast remains in the bread and where anythin which impairs the whiteness of the crumfi and flavor of the loaf is objectionable.

In the manufacture of sugar from sugar cane the stalks of the cane as they come from the field are crushed insuitable machines and then :run between rollers from which the sugar-containing sap is expressed. The crude juice thus obtained contains various impurities suchas particles of the cells and the tissue of the stalk, as well as particles of the leaves and grains of soil. From this juice the sugar is'made and the essential steps of the process, briefly described, consist in first adding to the juice a certain amount of lime which precipitates-out of the juice certain substances which interfere with the crystallization. The juice is then decolorized, which step is usually carried out'by blowing sulfur dioxide through the juice and also by the addition of bone blackwhich absorbs the Application filed May 8, 1928. Serial No. 637,56..

pigment-containing particles. After this treatment the juice is put through the evapocentrated, final residue constitutes the socalled crude molasses.

The molasses so produced contains a lar e portion of the extraneous matter present 1n the original juice, together with the mineral substances contained in the raw juice, and in large part, the lime, sulfur compounds and other substances added to the juice during therefining process,

Yeast grown in a solution made from the crude molasses is unfit for use" in break-making, for. the reasons which we have mentioned above. Efforts to-clarify and refine the crude, molasses for yeastrowin have heretofore proven unsuccessfu, chie y for the reason that no process has been devised which would at one operation-remove all" or the majority of the numerous diiferent kinds-of foreign substances in themolasses which render it -unfit for the growing of bak'ers yeast, and to subject the molasses to the number of successive. processes necessary to removev all the varlous ingredients, makes the rocess of clarification more expensive tnan t 1e production of yeast from suitable grain extracts which are in the main entirely satisfactoryfor the purpose,

- Our invention has for its object to provide a clarifying process for the molasses in which, 2

by a few simple and inexpensive operations the ingredients in the molasses which inhibit the yeast growing or adversely affect the quality of the yeast, are removed, the resulting product of our process being a yeast growing solution of much lower than the malt grain solutions eretofore used, but which willnevertheless produce a yeast of the best quality and of a fermenting power equal to or better than the standard yeast grown in the grain solutions.

The substances in the cane molasses which are deleteriousto the clarifying or to the yeast-growing are principally iron, sulfur dioxide, tannins. or tannin-like products, dextrins, gums, pigments, clay, and aluminum, if in excessive quantity. I

Certain substances in the molasses also interfere with the filtration of the molasses even when diluted 20 to 30 times, and without filtering it is impossible to remove the exproduction cost traneous impurities such as clay, carbon, and the particles of'the stalk. and leaves of the cane which are unavoidably-present in. the- .molasses'. {It is al'soriecessary to "filter the solution 1 during ,the yeast manufacturing process and a solution which is difi'icult of im-' stantially-all ofthe nitrogenous. content" aii dfthe phosphorus containing ingredients.

Thirdly, the process must be such as to make.

filtration er he solution easy. F ourthly, the

processfmus't be such as to remove the-delefinally, such substances as are used in the treatment must notthemselves be toXicor in any way deleterious to the growth of yeast or of a character which, when the yeast is added to the bread, will constitute foreign matter or imgurities in the bread.

or improved process for the treatment of cane molasses is founded primarily on the discovery that sodium silicate of a composition in which it may bereadily obtained in the market, will remove'fromthe molasses solution a number of its aforementioned deleterious ingredients and Wlll also .preclpitate from the molasses the ingredients which" prevent its filtration, whereby the solution after thetreatment with the sodium silicate may be readily filtered and-the other remaining foreign matter largely removed. I

dout in various ways and in the following specification we have pointed out in detail a procedure which we have found in practice results in a solution which will produce-a yeast which will mature the dough in a shorter time than the yeast grown in the ordinary grain solution and will also produce a better loaf volume than can be obtained with the standard compressed yeasts now used.

Commercial sodium silicate as obtained on the market is not of a definite chemical composition, the exact composition and the exact proportions of the silicate as such not being well known or easily determinable. Difier- 1 ent brands of silicate contain the silicon and sodium in varying proportions and the brands are gradedand soldon the basis of the total percent of sodium (calculated as Na O) and silicon (calculated as S'iO present. We havefound that the brands which are rated comparatively low in Na,() and comparatively high in SiO, are preferable for our purposes. Beneficial results may be obtained with any grade of commercial sodium silicate largely on having the Na O content within the range of 6 to 18 percent and the SiO content from 24 to 40 percent.

The cane molasses to be clarified is diluted by the addition of Water preferably not less than three times the volume of the molasses.

The degree of dilution may be as greatas desired, but it is preferablenot toadd morewater than desired'in the solution as it is to be subsequently used for the yeast-growing process.

The quantity of silicate to be added depends the degree of alkalinity of the re-' sulting solution which, in turn, depends on the I 7.7-pH to 12 pH. terious "ingredients without the necessity of repeated and prolonged operations which make theicost of treatment prohibitive; and

fined sugar solutions have heretofore been successfully used.' WVhen so used any of the various ammonium compounds and phosphorus-con'taining compounds and other mineral salts heretofore employed may be used to supply the ammonium,-phosphorus and mineral requirements for yeast growth.

- The clarified molasses solution may also bemixed with malted grain solution. A pro portion of 60% clarified molasses solution to 40% grain solution forms a suitable medium for the yeast growth.

VVhileour clarifying process may be varied within certain limits as we have indicated above, we have found the'following procedureto give excellent results. The crude cane mo 'lasses is diluted with five parts by weight of water to one part of molasses. That is to say, to 200 grams of cane molasses we add 1000 cc. of water. To this solution we add about 25 grams of commercial silicate of approximately the formula Na O, 8%, SiO,, 30%, the quantity of silicate being varied somewhat with difierent cane solutions so as to produce a resulting alkalinity equivalent to a pH value of about 8.4. The mixture is heated for several minutes which causes the precipitate to increase in volume and to finally become flocculent and curdy. Also, the boiling drives off volatile substances in the mixture which would give an unpleasant odor to the yeast.

The resulting filtrate may be used for making the yeast-growing solution Without further treatment, but we have found that its quality may be improved by certain addi-' 'tional steps ill-those cases where the original molasses contains impurities, particularly iron and coloring materiahin excessive quan- An alkaline carbon may be used or the solution may be made slightly acid and an acid carbon used. v

Iron in any form, even 1n very small amounts, is particularly unfavorable to the yeast. The'yield and baking strength are not only reduced but the yeast is dark in color and unsuited for bread-making. This;

is probably'due to the fact that the iron unites with. the tannin or tannin-like substances present in the cane solution, producing darkcolored compounds. Where the iron and tannins are present in the molasses in large quantity it is desirable to employ an additional step in'the treatment of the molasses solution to assist in the removal of these impurities. One form of treatment which we have found effective is to add to the sugar solution before the silicate is added, small quantities of' gelatine or hydrolyzed glue, together with small amounts of ammonium hydroxide or ammonium sulfide. The gelatine-or glue serves to throw out some of the tannins while the ammonium compound pretially the same manner. The cheaper cost cipitates a portion of the iron whereby the silicate treatment is rendered more effective. Since cane molasses or black strap is usually acid in reaction and certain preliminary treatments may increase this acidity, it is often desirable to renderthe molasses alkaline prior to the silicate treatment.

This may be done by the addition of ammonium or sodium or other suitable hydroxide or some cheap and suitable phosphate in sufficient quantity to bring the alkalinity to such point that the addition of the sodium silicate will bring the alkalinity of'the mixture for filtration to the desired pH value of 8.4. The hydroxide or phosphate also serves the purpose of precipitating the iron com-' I pounds and pi ments, so that they will be more completey removed by 'the silicate treatment.

We have described our improved process of clarification in detail, whereby the process -may be readily carriedout and the best re-' sults obtained, but it will beunderstood that '55 the invention is in no wise limited to such detailed procedure except in so faras defined in the appended claims.

It will be understood, of course, that potassiumsilicate may be employed in lieu; of sodium silicate, if desired, and in substan- .ofthe sodium silicate, however, makes it commercially more suitable for carrying out theprocess. Although in the foregoing, reference'has frequently been made to sodium are to be generally understood as including such substances as are known to be equivalents for the same or analogous purposes.

' We claim:

1. The process of clarifying cane molasses to render it suitable for yeast manufacture, which comprises in adding to a dilute solution of molasses a. quantity of sodium silicate sufficient to render the resulting mixture alkaline within the limits represented by a pH value of from 7.7 to 12, then heating the mass and filtering while hot.

2. The process of clarifying cane molasses to render it suitable for-yeast manufacture, which comprises in adding to a dilute solution of the molasses a quantity of sodium silicate sufficient to render the resulting mixture alkaline to substantially a pH valuation of 8.4, then heating the mass-and filtering while hot.

'3. The process of clarifying cane molasses to render it suitable for yeast manufacture, which comprises in adding to a dilute solution of the molasses a quantity of sodium silicate'of the formula represented substantially by 8 parts N a O to 30 parts SiO sufficient to render the resulting mixture to substantially a pH valuation of 8.4, then heating the mass and filtering while hot. p

4;. The process of clarifying cane molasses to render it suitable for yeast manufacture,

which comprises in diluting the molasses with five times its weight of water, adding to the mixture about 2% by weight of commercial sodium silicate of the formula-represented substantially by 8% Na O and 30% SiO boiling the mixture for several minutes and filtering while hot. Y

5. In a process of clarifying cane molasses to render it suitable for yeast manufacture, the-steps which consist in treating the dilute molasses with ammonium hydroxide and gelatine, adding to the mixture a quantity of commercial sodium silicate, and thereafter filtering to remove precipitated and suspended impurities.

.6. In a process for the clarification'of cane molasses to render it suitable for yeast manufacture, the step which consists in adding commercial gelatine to a dilute molasses solution. V i

7. The process of clarifying cane molasses to render it suitable for yeast manufacture, which comprises adding .to a dilute solution ofm'olasses 2% by weight of sodium silicate of the formula represented substantially by 8% Na O and 30% SiO boiling the mixture" and filtering.

8. The process of clarifying cane molasses having an acid reaction to render it suitable an alkalinity of about pH 8.4, heating the for yeast manufacture, which comprises dimixture to boiling and filtering while hot. luting molasses with five times the quantity In testimony whereofwe afiix our signa- 10 of Water, adding sodium hydroxide until the tunes.

v 5 solution reacts alkaline, then adding sodium CHARLES HOFFMAN.

silicate of a formula represented substantially CHARLES N. FREY. by 8% Na O and 30% SiO sufficient to give FRANK MERRILL HILDEBRANDT. 

